Pothead



Oct. 5, 1937. J, B, WEBB E1' AL 2,095,045

POTHEAD Filed May 14, 1936 /j f if; INVENTORS 7 if g 7 c/H/v IVI/E55, 1O/ HUGH WJD/1F 4 l i 4 BY @f l M I A i ATTORNEYS Patented Oct. 5, 1937PATENT OFFICE POTHEAD John B. Webb, Dobbs Ferry, and Hugh W. Papst, NewYork, N. Y., assignors to Anaconda Wire & Cable Company, NewYork, N. Y.,a corpo'- ration of Delaware Application May 14, 1936, Serial No. 79,688

3 Claims.

This invention relates to electric potheads and more particularly to animproved means for sc curing insulators thereto. Potheads are utilizedto terminate oil-filled or oil-impregnated cables and to provide meansto split the cable into two or more current paths. The usual potheadcomprises a bell and cap composed of metal. Means are provided to jointhe bell and cap together in a duid-tight seal. The bell is providedwith a nipple through which the cable extends to the interior of thebell and the cable sheath is secured to the nipple in a huid-tight seal.The cap is provided with a plurality of openings through which extendhollow insulators comprised of dielectric material and means areprovided to seal the insulators to the cap in a duid-tight joint. Theseveral branch circuits taken oil' from the cable are carried outthrough the cap by conductors extending through the said hollowinsulators.

Heretofore in the art it has been customary to seat the insulatorswithin the openings in the cap and to seal the space between the outersurface of the insulators and the cap with some kind of sealingcomposition, cement or plastic. To facilitate this it has been customaryto roughen the exterior surface of the insulator to aid the bonding ofthe sealing composition to the insulator surface. This method ofmounting the insulator in the cap produces a substantially permanentstructure which is essentially weak mechanically and where it is laterfound that the seal is not fluid-tight or where it is necessary toreplace the insulator, the entire structure must be returned to thefactory for repairs. This causes great inconvenience and expense whichis one of the objects of this invention to eliminate.

Another object of this invention is to provide means to detachablysecure the said insulators to the cap in a fluid-tight joint. Stillanother object of this invention is to provide an improved means forsecuring the insulators in the said cap openings whereby the same may bereadily attached and detached, so that repairs and replacements may beeasily made thereto in the iield and with minimum equipment. Otherobjects and advantages will be apparent as the invention is more fullydisclosed.

Before further disclosing the present invention, reference should bemade to the accompanying drawing wherein:-

Fig. 1 is an elevation of a pothead partly in section in which theimproved meansv of the present invention is incorporated; Fig. 2 is adetailed cross-sectional view illustrating the improved means of thepresent invention; Fig. 3 is an enlarged plan view of one of theelements of the said means; Fig. 4 is a. vertical section through thesaid element; and Fig. 5 is an elevational view of an insulator modifiedin accordance with the present invention.

Referring to Fig. 1, the pothead comprises a bell I formed of cast metaland provided with a nipple 2 through which the cable extends to theinterior of the bell. The outer sheath of the cable which is usuallycomprised of lead is secured to the said nipple in a fluid-tight joint,usually a wiped lead joint. Nipple 2 is usually made separate asindicated and means are provided as indicated at 3 to attach the nipple2 to the bell i in a fluid-tight joint.

The pothead is also provided with-a cap 4 provided with a plurality ofopenings through which insulators 5 extend and means indicated at 6 areprovided to secure the cap 4 to the bell i in a. fluid-tight joint.Means also must be provided to secure insulators 5 within the openingsin cap 4 in a duid-tight joint.

In accordance with the present invention the insulators 5 are secured inthe openings in cap 4 in such manner as to be readily detached andattached to provide for the quick and easy repair and replacement of thesame at the point of installation of the pothead in the field.

Referring particularly to Fig. 2, we provide each cap opening 1 with anannular shoulder extension l having outer and inner bearing surfacessubstantially as indicated, and we provide insulator 5 with an annularextension 9 having a bearing surface adapted to engage the outer bearingsurface of annular shoulder il and we interpose between said engagingsurfaces a gasket I0.

We then provide means to mechanically move the said insulator and caprelative to each other in such manner as to bring the two engagingsurfaces together thereby compressing gasket lil therebetween obtainingthereby a fluid-tight seal therebetween, the said means providing forthe retention of the insulator and cap in this relation.

` As indicated in Fig. 5, this is accomplished most simply by formingdiametrically opposite grooves Ii in the peripheral surface of insulator5 at a distance below the shoulder 9. Preferably the bottom of thegroove is provided with bearing seat i2 as will more fully be described.We then providea split ring element I3 (Fig. 3) consisting of twosimilar halves A and B, the exterior surface of the ring being threadedas indicated in Fig. 4 and the inner periphery being provided withdiametrically opposite bearing extensions I4, I4 the under surface ofthe said extensions being adapted to engage. the said bearing seats I2in grooves I I, substantially as indicated in Fig. 4.

We then provide a threaded nut I having threads adapted to engage thethreaded surface of split ring I3 in the manner indicated in Fig, 2 andhaving an outside diameter permitting the nut to extend within opening Iof cap 4 and to bear upon the inner bearing surface of extension 8. Uponthe threading of nut I5 upon split ring I3, the end of the nut I5contacts with the inner bearing surface of shoulder 8 and bearingextensions I 4 engaged in grooves II of insulator 5 thereupon operate tomove insulator 5 downward- 1y. Shoulders 8 and 9 are thus broughttogether and compress gasket lhtherebetween, thereby forming arluidtight seal.

The engaging of the. bearing recess in the under side of bearingextensions I4 with the bearing seat I2 in groove II prevents rotation ofthe insulator about its longitudinal axis.

It is apparent that the means provided to detachably secure insulator 5in openings 'I of cap 4 may be widely modified without essentially de.-parti'ng from the present invention and all such modifications arecontemplated as may fall within the scope of the following claims:

What we claim is: Y

1. In a pothead including a bell and cap and means to join the twotogether in a uidproof seal, a plurality of insulators and means todetachably secure said insulators to the said cap in a fluidproof sealwith one end of said insulators 'extending through the cap to theinterior thereof, said means to detachably secure comprising an openingin the cap through which the `said insulator end may extend, an annularshoulder extension about said opening, an annular shoulder extensionabout the periphery of ksaid insulator end adapted to engage said rstannular shoulder, an annular gasket adapted to be interposed between theengaging surfaces of said shoulders, a split ring element having athreaded outer surface and means to engage the outer periphery of saidinsulator end below said annular shoulder thereon, and a threaded nutadapted to engage with the threaded outer surface of said splitringelement and to bear upon the under side of said cap member to therebyobtain relative movement of the insulator and capV bringing the engagingsurfaces of said shoulders into compressive contact on opposite sides ofsaid gasket. 2. In a pothead including a bell` and cap and means to jointhe two together in a luidproof seal, a plurality of insulators andmeans to detachably secure said insulators to the said cap in afluidproof seal with one end of said insulators extending through thecap to the interior thereof, said means to detachably secure comprisingan opening ln the cap through which the said insulator end may extend,an annular shoulder extension about said opening, an annular shoulderextension about the periphery of said insulator end adapted to engagesaid rst annular shoulder, an annular gasket adapted to be interposedbetween the engaging surfaces of said shoulders, diametrically oppositegrooves in the periphery of said insulator end below the said annularshoulder thereon, a split ring element yhaving va kthreaded outersurface'and an inner surface provided with means to engage saidoppositeI grooves, and a threaded nut adapted to engage with thethreaded outer surface of said split ring element and to bear upon theunder side of said cap member to thereby obtain relative movement of theinsulator and cap bringing the engagingsurfaces of said shoulders intocompressive contact on oppositesides of said gasket.

3. In a pothead including a bell .and cap and means to join the twotogether in a uidproof seal, a plurality of insulators and means todetachably secure said insulators to the said cap in a fluidproof sealwith one end of said insulators extending through the cap to theinterior thereof, said means to detachably secure comprising an openingin the cap through which the said insulator end may extend, an annularshoulder eX- tension about said opening, an annular shoulder extensionabout the periphery of said insulator end adapted to engage said firstannular shoulder, an annular gasket adapted to be interposed between theengaging surfaces of said shoulders, diametrically opposite grooves inthe periphery of said, insulator end below Ythe said annular shoulderthereon, bearing seats in said grooves, a split ring element having athreaded outer surface and an inner surface provided with diametrivcallyopposite bearing extensions having bearing recesses on the under sidethereof adapted to engage in said groove and upon said bearing seatstherein, and a threaded nut adapted to engage with the threaded outersurface of said split ring element and to bear upon the under side ofsaid JOHN B. WEBB; HUGH W. PAPST.

